Hand operated press with selectively operated force applying means



March 3, 1959 P. c. NELSON 2,875,808

HAND OPERATED PRESS WITH SELECTIVELY OPERATED FORCE APPLYING MEANS Filed July 25, 1955 5 Sheets-Sheet 1 INVENTOR PAUL C. NELSON ATTORNEYS March 3, 195 P. c. NELSON 2,875,808

HAND OPER D PRESS WITH SELECTIVE-LY OPERAT FORCE APPLYING MEANS 3 Sheets-Sheet 2 Filed July 25, 1955 FIG. 2

INVENTOR PAUL G. NELSON ATTORNEYS NELSON HAND OPERATED PRESS WITH SELECTIVELY March 3, 1959 P. c.

OPERATED FORCE APPLYING MEANS s Sheets-Sheet 8 Filed July 25, 1955 INVENTOR PAUL C. NELSON ATTORNEYS United States PatentO r' p 2,875,808 lcfi Patented Mar. 3, 1959 HAND OPERATED PRESS WITH SELE'CTIV ELY OPERATED FORCE APPLYING MEANS Paul C. Nelson, Lake City, Minn., assignor to ONeil- Irwin Manufacturing Company, Lake City, Minn., a corporation of Minnesota Application July 25, 1955, Serial No. 524,092

3 Claims. (Cl. 153-21) The herein disclosed invention relates to hand operated presses and particularly to presses adapted to be used as brakes for'bending sheet metal.

In the operation of a brake or punch press, considerably more pressure is required at the end of the power stroke to iron out the corner of the metal when the press is used as a brake or to penetrate the metal when the press is used as a punch press. The instant invention provides a construction whereby either rapid movement of the ram of the press with a lesser force or greater force with less rapid movement can be procured at will.

An object of the invention resides in providing a shaft rotatable to procure movement of the ram and a handle connected to said shaft whereby the ram maybe directly moved by rotating the shaft and in further providing a toggle mechanism operative upon a member rotatable with said shaft and serving to increase the force adapted to be exerted on the ram.

Another object of the invention resides in providing a ratchet wheel movable with said shaft, a pivoted lever having a pawl pivoted thereto and engageable with the teeth of said ratchet wheel and forming with said lever a toggle mechanism and in providing a handle connected to said lever whereby said lever may be operated.

- A feature of the invention resides in providing a detent engageable with the ratchet wheel and serving to prevent reverse movement of said shaft and in further providing an arm on said detent together with a cam movable with said lever and serving to disengage the detent from the ratchet wheel when the lever is moved into its inoperative position.

Other objects of the invention reside in the novel combination and arrangement of parts and in the details of construction hereinafter illustrated and/or described.

In the drawings: a t

Fig. 1 is-a side elevational view of a press illustrating anembodiment of the invention applied thereto.

Fig. 2'is a view similar to Fig. l with portions of the frame cut away to illustrate the operating mechanism of the press.

Fig. 3 is a fragmentary view of the structure shown in Fig. l with the parts in altered position. a

Fig. 4 is a view similar to Fig. 3 drawn to a greater scale and showing the parts in still diiferentpositions;

' Fig. 5 is a view similar to Fig. 4 showing theparts in still different positions.

The press illustrated in the drawings comprises a frame which consists of two side frame members 11 and 12'. These frame members are in the form of plate-like castings and rest upon a plate 13. Screws 14 passing through said frame'members and screwed into said plate secure the parts together. In addition, a rear crossbar 15 is employed which is held attached to said framemembers by means of screws 16. Another transverse crossbar 17 is employed at the front of the press which is held attached to said frame members by means of screws 18. Formed on ,rotatably support a power shaft 21.

At the forward portions, of the frame members 10 and 11 are mounted two posts 22 which serve as guides and which are attached to said frame members by means of screws 23. Extending across these posts is a ram 24 which has bosses 25 extending rearwardly therefrom and which are bored to receive the posts 22. By means of this construction the ram is guided in a vertical direction. The ram 24 is further formed with lugs 26 extending upwardly therefrom and which have pivoted to the upper ends thereof by means of pintles 27, two levers 28, one at each end of said ram. The levers 28 are in turn pivoted by means of shouldered bolts 29 to the frame 10, said bolts extending through and being secured to the side frame members 11 and 12. The holes receiving the pintle 27 and bolts 29 are sufliciently loose to permit of reciproeating the ram 24 along the posts 22 and to perform the desired operation.

Formed on the shaft 21 are two eccentrics or cranks 31. These cranks have mounted on them connecting rods 32 which in turn are pivoted by means of pintles 33 to the levers 28. It will be readily comprehended that as the shaft 21 is rotated, the eccentrics 31 cause the levers 28 to be moved downwardly and the ram 24 to be moved in the desired manner.

Secured to the crossbar 17, by means of bolts 34, is a bed or tool holder 35. This tool holder has mounted in it a bending tool 36 consisting of a bar provided with a V-shaped notch 37 extending along the same. Cooperating with the tool 36 is a complemental tool 38 similarly constructed and which is formed with a V-shaped edge 39 adapted to enter the notch 37. Tool 38 is held attached to the ram 24 by means of a clamp 41. The tool holder 35 may be adjusted for elevation by means of adjusting screws 42 which are screwed into projections 43 formed on the side frame members 11 and 12 and which engage the under sides of said tool holder and support the same.

To properly position the work to be bent, a gauge 44 may be employed which is adjustably supported in blocks 45 attached to the frame members 11 and 12.

The invention proper utilizes a rod 46 which serves as a handle and which is received in a boss 47 formed on a head 48. Head 48 is formed with a bore 49 which receives shaft 21 and is further constructed with a kerf 51 at its outer end intersecting said bore. A screw 52 screwed into the end of said head clamps the head upon the end of the shaft 21. A key 53 engaging said head and shaft prevents relative rotation of the parts. By means of this construction, the shaft 21 may be rotated manually by manipulating handle 46 and the ram raised and lowered at will at a fairly rapid rate.

Attached to the side frame member 11 is a shouldered stud 54 which is screwed into said frame member and which forms a bearing for a lever 55 rotatably mounted thereon. This lever has a boss 56 extending outwardly therefrom and which is bored to receive one end 57 of a rod 58 having a handle 59 at its outermost end. The axis of the stud 54 is parallel to and spaced from the axis of the shaft 21. The end 61 of lever 55 has pivoted to it by-means of a pintle 63 a pawl or link 64. This pawl is formed at its free end with an abutment 65 which is adapted to engage any of a number of teeth 66 formed on a ratchet wheel 67. The wheel 67 is mounted on shaft 21 and rigidly secured thereto and the teeth 66 lie substantially along the circle 62 of said teeth for a portion of the movement of saidlever. The pawl 64 is lirnited'in movement with referenceto the lever 55 by means of an adjusting screw 68 screwed intoa lug 69 formed onthe lever-.55. When" the lever 55 is in its inoperative position, 'as' shown in Fig. l, pawl 64 is raised'above the ratchet wheel 67 by means of said screw and shaft 21 may be rotatedby means of the handle 46.

7 The link 64 and the lever 55form' a toggle mechanism which, when the parts are arranged so that a line passing substantially through the locality of engagement of said pawl with the axis of the pintle 63 and a line passing through said axis and the axis ofthe stud 54 lie substantially in alignmen'tfas shown'in' Fig. .3, exerts an exceedingly great'force on the ratchet wheel '67 and a correspondingly great force on the work being bent.

To prevent reverse movement of the shaft 21 while the press is used for making a bend, a detent 71 is employed which is pivoted through a shouldered stud 72 to frame member 11. This detent has an abutment 73 adapted to engage any of the teeth 66 of the ratchet wheel 67 and when in engagement therewith restrains movement of shaft 21 in a reverse direction. Extending rearwardly from the detent 71 is an arm 74 which is adapted to be engaged by means of a cam 75 formed on the lever 55. This cam serves to raise the abutment 73 out of engagement with the teeth 66 and to free the shaft 21 when the lever 55 is moved to its inoperative position as shown in Fig. l. The detent 71 is considerably heavier than the arm 74 and the same is urged into engagement with the teeth 66 by gravity. Due to the arrangement of parts, the toggle mechanism may be brought into action at any position of the ram 24.

The operation of the invention is as follows: A piece of sheet metal to be bent, such as is indicated at 76 in Fig. 1, is inserted into the pressand caused to rest upon the tool 36 with its edge engaging the gauge 44. The lever 46 is now rotated to a substantially horizontal position as shown in Figs. 3 and 4. This places an initial bend in the work 76 so that the same assumes the position shown in dotted lines indicated by the reference numeral 77 in Fig. 3. Upon moving the handle 59 forwardly, cam 75 is disengaged from the arm 74 and detent 71 drops into engagement with the teeth 66 of the ratchet wheel 67. Further movement of said lever brings the abutment 65 into engagement with one of the ratchet teeth 66 as shown in Fig. and as indicated in dotted lines by the reference numeral 78 in Fig. 3. Additional movement of said lever causes the pawl 64 to turn the wheel 67 and to further rotate shaft 21. Such rotation forces the tool 38 further into the notch 37 and irons out the bend in the work 76 causing the work to take the form indicated by the reference numeral 79 in Fig. 3. Detent 71 during such movement'drops behind another tooth of the ratchet wheel 67 and holds the work in position. The operation is now completed and the work may now be released by swinging the handle 59 upwardly to the position shown in Figs. 1 and '4 This causes the cam 75 to engage arm 74 and to disengage the detent 71 from the ratchet wheel'67. The shaft 21 may now be turned by manipulating handle 46 and the tool 38 raised to the position shown in Fig. 1. The bent work may then be removed from the machine.

The advantages of the invention are manifest. For small work requiring considerable pressure, the machine may be readily operated by hand and without undue exertion by the operator. For extremely light work, the handle directly connected to the shaft may be employed, and where additional force is required the second handle may be brought into action. The invention is extremely simple in operation and will not readily get out of order. The device can be manufactured at an economical cost.

Changes in the specific form of the invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of the invention.

Having described the invention, what is claimed as new and desired to be protected by Letters Patent is:

1. In combination, a frame, a'shaft journaled for rotation in said frame, a bed carried by said frame, a tool guided for movement toward and from said bed, means operated by said shaft and connected to said tool, said means upon rotation of said shaft moving said tool-toward and from-the bcd,--a toothed ratchet wheel 4 I fixed on said shaft, a lever, pivot means for one end of said lever and having its axis spaced from and substantially parallel with the axis of the shaft, a pawl, pivot means between one end of said pawl and the other end of said lever, the other end of said pawl being normally free from said ratchet wheel and upon initiation of movement of said lever being brought into engagement with the teeth of said ratchet wheel and being movable in the direction of movement of said teeth, the pivot means for said lever and pawl being arranged and said parts constructed so that the pawl and lever may occupy a position in which a line passing through the locality of engagement of said pawl with a tooth of said ratchet wheeland the axis of said pivot means for said pawl comes substantially into alignment with a line passing through the axis of said pivot means for the pawl and the axis of the pivot means for said lever, a handle connected to and serving to rotatesaid lever, andmanual means for rotating said shaft when said link is free from said ratchet wheel.

2. In combination, a frame, a shaft journaled for rotation in said frame, a bed carried by said frame, a tool guided for movement toward and from said bed, means operated by said shaft and connected to said tool, said means upon rotation of said shaft moving said tool toward and from the bed, a toothed ratchet wheel'fixed on said shaft, a lever, pivot means for one 'end of said lever and having its axis spaced from and substantially parallel with the axis of the shaft, a pawl, pivot means between one end of said pawl and the other end of said lever, a stop acting between said lever and pawl and holding the other end of said pawl free from said ratchet wheel when said lever is in one position and upon initiation of movement of said lever from such position being brought into engagement with'the teeth of said ratchet wheel, said pawl and lever being of a combined length such that a line passing through the locality of engagement of said pawl with a tooth of said ratchet wheel and the axis of said pivot means for said pawl comes substantially into alignment with a line passing through the axis of said pivot means for the pawl and the axis of the pivot means for said lever when the lever is in another position, a detent pivoted to said frame and engageable with the teeth of said ratchet wheel to restrain reverse movement of said shaft, a handle connected to and serving to rotate said lever, and manual means'for rotating said shaft when said pawl is free from said abutment.

3. In combination, a frame, a shaft journaled for rotation in said frame, a bed carried by said frame, a tool guided for movement toward and from said bed, means operated by said shaft and connected to said tool, said means upon rotation of said shaft moving said tool toward and from the bed, a toothed ratchet wheel fixed on said shaft, a lever, pivot means for one end of said lever and having its axis spaced from and substantially parallel with the axis of the shaft, a pawl, pivot means between one end of said pawl and the other end of said lever, a stop acting between said lever and pawl and holding the other end of said pawl free from said ratchet wheel when said lever is in one position and upon initiation of movement of said lever from such position being brought into engagement with the teeth of said ratchet wheel, said pawl and lever being arranged and said parts constructed so that a line passing, through the locality of engagement of said pawl with a 'toothof said ratchet wheel and the axis of said pivot means for said pawl comes substantially into alignment with a line passing through the axis of said pivot means for the pawl and the axis of the pivot means for said lever when the lever is in another position, a detent pivoted to said frame and engageable with the teeth of said ratchet wheel. to restrain reverse movement of said shaft, a cam fixed relative to and movable with said lever and engageable with said arm to-dislodge said detent from engage;

ment with said ratchet teeth when the lever is moved into a position away from said ratchet wheel, a handle connected to and serving to rotate said lever, and manual means for rotating said shaft when said pawl is free from said abutment.

References Cited in the file of this patent UNITED STATES PATENTS 32,262 Edwards and Hornet May 7, 1861 6 Barmore Aug. 25, 1885 Sherburne Feb. 26, 1907 Templeton May 7, 1912 Eaton Feb. 1, 1916 Shipman Nov. 7, 1944 Neal May 31, 1949 Hey Oct. 31, 1950 

